Packet Switching In Computer Networking

Packet Switching In Computer Networking

PACKET SWITCHING  :  Packet Switching is a digital networking communication method that groups all transmitted data, regardless of content, type or structure in a suitably sized block called "Packet".

Packet switching features delivery of variable bit rate data stream over a shared network, when traversing network adapters, switches, routers etc.

Packets are buffered and queued, resulting in variable delay and throughput depending  on the traffic load in the N/W .

Best example of packet switching is Internet  and LAN.

Division of Packet Switching 

Circuit Switching            Packet Switching         Message Switching

  

  

Packet Switching

ConnectionLess                                              Connection Oriented

  (datagram)                                                        (virtual circuit)

 ConnnectionLess Packet Switching :

 All packets have header including all address information as source address, destination address and port number.

Each packet treated independently.

Connection less protocol are => Ethernet, Ip & Udp  

 Connection Oriented Packet Switching :

 A connection is defined and preallocate in each involve node during a connection phase before any packet is transferred.

All packet include connection ID rather than address info.

 Connection Oriented protocols are => x.25, frame-relay

X.25 : 

It is a reliable protocol based on node to node automatic repeat request.  

 It is a network layer protocol.

Frame Relay :

 Non reliable protocol 

It is a further development of x.25, fast & more cost effective.

It is a data link layer protocol.

It does not provide logical address & routing , it is only used for semi-permanent connections.